1. Field of the Invention
The present invention relates generally to filtration devices and systems, and particularly to a liquid recovery filter having an inlet and outlet vent and purge ports for the drainage and recovery of unfiltered and filtered liquids from the filter housing and core after filtering operations.
2. Description of the Related Art
Innumerable filtration devices and systems have been developed for the cleaning and purification of a wide range of gases and liquids. One area that requires extremely high quality filtration is in the field of pharmaceutical manufacture, where a number of different liquids are involved in the manufacturing processes of a large number of drugs and medications. These various liquids are often quite costly to produce, and as a result, much effort is expended to recover such liquids during the manufacturing process, insofar as practicable.
One of the means used to recover such liquids is through the use of various filters. The liquid is passed through the filter(s) and the purified liquid is recovered from the downstream or outlet side of the filter. The filter elements of such filters conventionally have a generally toroidal configuration, the unfiltered liquid passing through the filter element from the outside and through the filter material to the hollow inner core, although other configurations are certainly feasible. One problem with such filter configurations is that when the filter is replaced, there is a volume of purified, filtered liquid still contained in the hollow core of the filter element within the filter housing or shell, as well as unfiltered liquid remaining within the filter housing and outside of the filter element. These liquids are often quite valuable, as noted further above, and discarding these liquids when the filter is periodically removed and replaced results in the loss of a considerable amount of valuable liquid over some period of time.
Thus, a liquid recovery filter solving the aforementioned problems is desired.